Bicycle frame



FIG. 1 of the drawings is a perspective view showing the front, top, and left side of a bicycle frame embodying the design of my invention;

FIG. 2 is an elevation view of the right side;

FIG. 3 is an elevation view of the back; and,

FIG. 4 is a plan view of the bottom. 

I claim the ornamental design for a bicycle frame, as shown. 